The St. Louis-Cape Girardeau CCOP is a consortium of four hospitals in two separate bi-state health service areas serving parts of eastern Missouri and western Illinois. The Investigators from the St. Louis Metropolitan area are affiliated with one or both of the two hospitals in the consortium and have worked together for the past eighteen years in cancer treatment research protocols and more recently, in cancer control research studies. The Cape Girardeau Investigators have worked with CCOP for the past nine years and are affiliated with two hospitals in that city. During the next five years we expect to accrue at least sixty credits per year for cancer treatment research protocols of the NSABP and SWOG and at least seventy five credits (new participants and follow-up) per year for cancer control and prevention studies. These cancer control credits will be derived primarily from our participation in the Breast Cancer Prevention Trial-1, Prostate Cancer Prevention Trial-1 and the Breast Cancer Prevention Trial-2. We will continue to provide high quality data to the Southwest Oncology Group and the National Surgical Adjuvant Breast and Bowel Project which are our research bases, utilizing the data management system developed during the past eighteen years. In summary, we will continue our excellent performance of the past eighteen years in cancer treatment research studies and extend our more recent participation in cancer control and prevention trials. The past experience and capabilities of the Investigators and Clinical Research Associates provides a strong base for continuing development of this Community Clinical Oncology Program.